Flexible stay-bolt for boilers.



UNITED STATES PATENT OFFICE.

BENJAMIN E. D. STAFFORD, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE FLANNERY BOLT COMPANY, OF PITTSBURG, PENNSYLVANIA.

FLEXIBLE STAY-BOLT FOR BOILERS.

' Specification of Letters Patent. Patented Feb, 21, 1911,

Application filed July 15, 1910. Serial No. 572,208.

To all whom it may concern:

Be it known that I, BENJAMIN E. D. S'rarrono, of Pittsburg, 'in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Flexible Stay-Bolts for Boilers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable othersskilled in the artto which it appertains to make and use the same.

My invention relates to an improvement in flexible stay bolts for boilers, the object being to provide improvements which will permit the bolts to be adjusted and locked after they have all been assembled so as to secure uniform tension on all the bolts, and which will also permit of ready inspection and testing of all the bolts from the outside.

With these and other objects in viewmy invention-consists in the details of construction and combinations of parts as will be more fully described and pointed out in the claims.

In the accompanying drawings, Figure 1 is a view in section through sections of the roof and crown sheets showing the bolt and its parts in side elevation and Fig. 2 is a. similar view with the sleeve cap and nut partly in elevation and partly in section,

and showing the nut locked-to the bolt.

1. represents the roof sheet,fand 2 the crown sheet of the boiler, and 3 the sleeve having a tapered and threaded end4-; mounted in a tapped hole in the roofv sheet. This sleeve is provided in a plane outside of'the roof sheet with an internal seat 5 curved in the arc of a circle on which the rounded head of the stay bolt rests, and its bore be: low said seat is made flarin downwardly as at .6 so as to permit of stricted movement of the bolt 7. The outer end of the sleeve is covered by a cap 8,

.lflhe bolt 7 is of the button head type as cc and unrefor engagement with a tapped hole in the 77 crown sheet 3, and is also provided at its upper and outer end with a threaded section 11 engaged by the removable rounded nut or head 9 of the stay bolt. This nut hasfiattened ends and curved sides as shown and isprovided'with the slots for a driver or. wrench by which it is turned. or held while being attached to the bolt 7. After the nut 01' head has been properly adjusted it is locked in place by upsetting the metal at the end of the bolt into one or both slots 12 of the nut or head 9 thus locking the latter against any movement. The bolt .7 is introduced through the crown sheet and if-desired suitable packing rings 13 may be interposed between the button' head 14 and the face of crown sheet 2.

In assembling the parts, after the bolt 7 and sleeve 3 have been secured in place the head 9 of the bolt is screwed onto the threaded end of the bolt and after the whole series of bolts have been so securedin place. the heads 9, which are in planes outside of the roof sheets may all be adjusted alike and .in this way prevent unequal tension on the bolts and sheets, and after the heads have been so adjusted they are locked by upsetting the metal at the ends of the bolts into the slots 12 as before explained. By projecting the bolts through the outer or roof sheets they are accessible for ready examination and inspection by simply removing the. caps 8. If inspection discloses a defective or broken stay, it can be removed by simply cutting out the metal from slot 12in the head and withdrawing the bolt through the crown sheet.

When first heating aboiler the crown sheet expands and carries with it the bolts. 7

By providing elongated recessesfor the heads, the movement of the bolts does not transmit its movement to the roof sheet but on the contraryprovides for differences in expansion between the crown sheet of the fire box and roof sheet of the boiler As the roof sheet heats up it also-expands-and carries-the sleeves out against the heads of the form, the headswill be firmly seated on the e sleeves. By this construction .I avoid all. excessive outward strains onthe roof sheet "when the'latter'is cold, and provide for practically uniform strains on all the bolts at all times and under all conditions.

It is evidentthat many slight changes might be resorted to in the relative arrangement of parts shown and described Without departing from the spirit and scope of my invention. Hence I wouldhave it understood that I do not wish to confine myself. to the exact construction and arrangement of,

parts shown and described, but

I Having fully described my invention what I claim as new and desire to secure by Letters Patent, is

1. A stay bolt structure comprising a sleeve threaded externally and provided internally with a rounded seat forthe head of the stay bolt, the said seat being in a plane above bolt, the said seat being in a plane above or beyond the externally threaded portion of the sleeve, a recessed cap for closing the outer end of said sleeve and a button head stay bolt, having a threaded upper end anda rounded head screwed onto said threaded end, and provided with a slot into which the metal of the bolt is upset for locking the head to the bolt.

3. A stay bolt structure comprising'a sleeve threaded externally and provided internally with a rounded seat for the head of the stay bolt, a cap havinga rounded or curved recess conforming to the recess in the sleeve,

for closing the outer end of the latter, and Y a button head stay bolt having a threaded upper end and a rounded head. screwed onto said threaded end and resting in the curved housing formed by the sleeve and cap.

In testimony whereof I have signed this specification in the presence of two subscribing Witnesses. BENJAMIN E. DSTAFFORD. Witnesses I I EDWIN S. Ryan,

\VM. Y. MoNABB. 

